Evaluating outcomes and toxicities for a newly implemented MRI-based brachytherapy program for cervical cancer

Dylan H Ross; Kayeromi Gomez; Grant Harmon; Michael L Mysz; Steven M Shea; Ari Goldberg; Margaret Liotta; Ronald Potkul; Abigail Winder; Brian Lee; Jacob Jackson; John C Roeske; William Small Jr; Matthew M Harkenrider

doi:10.1016/j.ygyno.2024.03.003

Evaluating outcomes and toxicities for a newly implemented MRI-based brachytherapy program for cervical cancer

Gynecol Oncol. 2024 Mar 15:183:33-38. doi: 10.1016/j.ygyno.2024.03.003. Online ahead of print.

Authors

Affiliations

¹ Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardin Cancer Center, Loyola University Chicago, Maywood, IL 60153, USA; Loyola University Medical Center, Maywood, IL 60153, USA.
² Loyola University Medical Center, Maywood, IL 60153, USA; Biostatistics Collaborative Core, Clinical Research Office, Health Sciences Campus. Loyola University Chicago, Maywood, IL 60153, USA.
³ Loyola University Medical Center, Maywood, IL 60153, USA.
⁴ Loyola University Medical Center, Maywood, IL 60153, USA; Department of Radiology and Medical Imaging, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
⁵ Loyola University Medical Center, Maywood, IL 60153, USA; Department of Obstetrics and Gynecology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
⁶ Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardin Cancer Center, Loyola University Chicago, Maywood, IL 60153, USA; Loyola University Medical Center, Maywood, IL 60153, USA. Electronic address: mharkenrider@lumc.edu.

PMID: 38492475
DOI: 10.1016/j.ygyno.2024.03.003

Abstract

Objective: We report an updated analysis of the outcomes and toxicities of MRI-based brachytherapy for locally advanced cervical cancer from a U.S. academic center.

Methods: A retrospective review was performed on patients treated with MRI-based brachytherapy for cervical cancer. EBRT was standardly 45 Gy in 25 fractions with weekly cisplatin. MRI was performed with the brachytherapy applicator in situ. Dose specification was most commonly 7 Gy for 4 fractions with optimization aim of D90 HR-CTV EQD2 of 85-95 Gy_{α/β=10 Gy} in 2 implants each delivering 2 fractions.

Results: Ninety-eight patients were included with median follow up of 24.5 months (IQR 11.9-39.8). Stage IIIA-IVB accounted for 31.6% of cases. Dosimetry results include median GTV D98 of 101.0 Gy (IQR 93.3-118.8) and HR-CTV D90 of 89 Gy (IQR 86.1-90.6). Median D2cc bladder, rectum, sigmoid, and bowel doses were 82.1 Gy (IQR 75.9-88.0), 65.9 Gy (IQR 59.6-71.2), 65.1 Gy (IQR 57.7-69.6), and 55 Gy (IQR 48.9-60.9). Chronic grade 3+ toxicities were seen in the bladder (8.2%), rectosigmoid (4.1%), and vagina (1.0%). Three-year LC, PFS, and OS were estimated to be 84%, 61.7%, and 76.1%, respectively.

Conclusion: MRI-based brachytherapy demonstrates excellent local control and acceptable rates of high-grade morbidity. These results are possible in our population with relatively large volume primary tumors and extensive local disease.

Keywords: Brachytherapy; Cervical cancer; MRI planning.